Studies are directed toward understanding the mechanisms by which estrogens are formed in peripheral (non-endocrine) tissues. Specifically, models are being sought in which the increased efficiency of estrogen production associated with obesity may be explained. Other studies are directed towards defining the role that binding of serum estrogens to sex hormone binding globulin (SBG) plays in limiting action. In particular, we are studying the consequence of reduced SBG levels in amplifying estrogen effects on target tissues.